Optical fiber connectors

ABSTRACT

An optical fiber connector sub-assembly a ferrule holder configured to hold a ferrule at a front portion of an optical fiber connector, a ferrule housing configured to slidingly receive the ferrule holder and configured to be coupled to an end of a fiber optic cable that includes an optical fiber, and a spring configured to be nonrotatably coupled with the ferrule holder and the ferrule housing. The spring is configured to prevent the ferrule from rotating relative to the end of the fiber optic cable while permitting the ferrule holder to slide axially relative to the ferrule housing, and the spring is configured to reduce a load on the ferrule when a load is applied to the fiber optic cable so as to prevent degradation of a signal being transmitted by the fiber.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of U.S. application Ser. No. 17/152,779,filed Jan. 19, 2021, pending, which claims the benefit of U.S.Provisional Application No. 62/962,242, filed Jan. 17, 2020, thedisclosure of which is hereby incorporated by reference herein in itsentirety. This application also claims the benefit of U.S. ProvisionalApplication No. 63/173,355, filed Apr. 9, 2021, the disclosure of whichis hereby incorporated by reference herein in its entirety.

BACKGROUND

The present disclosure relates to optical fiber connectors, for exampleSC fiber optic connectors, and to a method of forming and using suchconnectors.

The mechanical tolerances involved in terminating single mode opticalfiber are much tighter than those for multimode optical fiber.Therefore, while it is quite common for multimode optical fiber beterminated at the point of use, for example, at a user's premises or atan outside junction box, in most product applications, single modeoptical fiber is not terminated in the field. When single mode fibermust be terminated in the field, then it can take a skilled technicianbetween about 15 to 20 minutes to splice fibers together either by usinga V-groove clamp or expensive fusion welding equipment.

Single mode fiber is therefore often provided in a range of differentlengths, pre-terminated at both ends with a connector plug ready to pluginto a matching receptacle. Commonly, eight or twelve single modeoptical fibers may be bundled together in an optical fiber cable havingan outer protective tube inside of which the optical fibers run.

An example of such a connector is the “Subscriber Connector,” or SCconnector, originally developed by NTT®. SC connectors have convenientpush/pull style mating, and are approximately square in cross-sectionand with a 2.5 mm diameter ferule at the termination of the opticalfiber, surrounded by a plastic housing for protection. SC connectors areavailable in single or duplex configurations. The SC connector latchesinto a matching socket in a simple push motion. The push-pull designincludes a spring against which the ferrule slides within a plasticinner housing. This arrangement provides a reliable contact pressure atthe ferrule end and resists fiber end face contact damage of the opticalfiber during connection. The connector can be quickly disconnected byfirst pulling back an outer housing, which is slidable relative to theinner housing, to disengage a latch inside socket between the socket andthe inner housing, before pulling the optical fiber connector from thesocket. Until the latch is thus disengaged, the latch preventswithdrawal of the connector when the optical fiber cable is pulled in adirection away from the socket.

It is important to avoid bending optical fiber around curves having toosharp a bend radius, as this will increase optical losses and canpermanently damage the optical fiber. Optical fiber cables are thereforeoften routed inside a protective outer tube or conduit, which can haveminimum bend-limiting properties. Protective bend limiting conduitsnormally have an outer diameter of 8 mm or 10 mm tubes. Thecross-section of a standard SC connector has dimensions of about 7 mm×9mm, and even a small form factor SC connector is too large to fit insidethe inner diameter of a typical protective conduit.

Conventional optical fiber connectors comprise a rigid pushablestructure to allow for limited movement of the connector parts whilebeing pushed down stretches of duct. However, due to their rigidstructure, conventional optical fiber connectors suffer from signaldegradation when weight is added to the cable and the connector whilethe connector is transmitting a signal.

It may be desirable to provide an optical fiber connector with improvedsignal transmission capability when a load or force is applied to thecable, the boot, or a rear end of the connector. It may be desirable toprovide an optical fiber connector that mechanically isolates theferrule from the fiber optic cable to improve signal transmission. Itmay be desirable to provide an optical fiber connector that prevents theferrule and the fiber optic cable from rotating relative to one another.It may be desirable to provide a connector having a shortened length toreduce a load on the ferrule when a load or force is applied to thecable, the boot, or a rear end of the connector.

SUMMARY

In accordance with various embodiments of the disclosure, an opticalfiber connector sub-assembly includes a ferrule configured to hold anoptical fiber therein along an axis of an optical fiber connector, aferrule holder configured to hold the ferrule at a front portion of theconnector, a ferrule housing including a front portion configured toslidingly receive the ferrule holder and a rear portion configured to becrimped onto an end of a fiber optic cable that includes the opticalfiber, an inner housing configured to be coupled with the ferrulehousing, and a spring having a first end configured to be press fit ontoa radially outer surface of the ferrule holder and a second endconfigured to be press fit into a radially inner surface of the ferrulehousing. The ferrule holder, the ferrule housing, and the inner housingare configured to be rotatably fixed to one another, the ferrule holderis configured to slide axially relative to the inner housing, and theferrule holder and the ferrule housing are configured to move axiallyrelative to one another along the connector axis between limits definedby an interaction between the ferrule housing, the spring, and theferrule holder. The spring is configured to prevent the ferrule fromrotating relative to the end of the fiber optic cable while permittingthe ferrule holder to slide axially relative to the ferrule housing, andthe spring is configured to reduce a load on the ferrule when a load isapplied to the fiber optic cable so as to prevent degradation of asignal being transmitted by the fiber.

In some aspects, the spring is configured to bias the ferrule away fromthe ferrule housing along the connector axis.

In various aspects, a Subscriber Connection (SC) optical fiber connectorincludes the aforementioned optical fiber connector sub-assembly and anouter housing. The inner housing is configured to define a receptaclethat is configured to receive a socket that is configured to receive aprojecting portion of the ferrule, and the spring is configured suchthat the projecting portion of the ferrule is spring biased along theconnector axis towards the receptacle of the inner housing. The innerhousing is configured to be engaged within the outer housing, and theinner housing and the outer housing are configured to move relative toeach other along the connector axis between limits defined by aninteraction between the inner housing and the outer housing in order toprovide SC push/pull engagement/disengagement with a mating opticalfiber socket.

According to various aspects of the connector, the ferrule is configuredto be rotationally fixed with respect to the ferrule holder about theconnector axis, the ferrule holder is configured to be rotationallyaligned with respect to the outer housing so that the rotationalorientation of the ferrule with respect to the outer housing can be setduring assembly of the connector at one of one or more predefinedrotational orientations, and a rotational key is provided between theferrule housing and the inner housing.

In accordance with various embodiment of the disclosure, an opticalfiber connector sub-assembly includes a ferrule configured to hold anoptical fiber therein along an axis of an optical fiber connector, aferrule holder configured to hold the ferrule at a front portion of theconnector, a ferrule housing including a front portion configured toslidingly receive the ferrule holder and a rear portion configured toterminate an end of a fiber optic cable that includes the optical fiber,and a spring having a first end configured to be nonrotatably coupledwith the ferrule holder and a second end configured to be nonrotatablycoupled with the ferrule housing. The spring is configured to preventthe ferrule from rotating relative to the end of the fiber optic cablewhile permitting the ferrule holder to slide axially relative to theferrule housing, and the spring is configured to reduce a load on theferrule when a load is applied to the fiber optic cable so as to preventdegradation of a signal being transmitted by the fiber.

According to some aspects, the spring is configured to bias the ferruleaway from the ferrule housing along the connector axis.

In some aspects, the ferrule holder and the ferrule housing areconfigured to move axially relative to one another along the connectoraxis between limits defined by an interaction between the ferrulehousing, the spring, and the ferrule holder.

In various aspects, the optical fiber connector sub-assembly furtherincludes an inner housing configured to be coupled with the ferrulehousing. According to various aspects, the ferrule holder, the ferrulehousing, and the inner housing are configured to be rotatably fixed toone another. In some aspects, the ferrule holder is configured to slideaxially relative to the inner housing.

According to various aspects, a Subscriber Connection (SC) optical fiberconnector includes the aforementioned optical fiber connectorsub-assembly and an outer housing. The inner housing is configured todefine a receptacle that is configured to receive a socket that isconfigured to receive a projecting portion of the ferrule, the spring isconfigured such that the projecting portion of the ferrule is springbiased along the connector axis towards the receptacle of the innerhousing, and the inner housing is configured to be engaged within theouter housing, the inner housing and the outer housing being configuredto move relative to each other along the connector axis between limitsdefined by an interaction between the inner housing and the outerhousing in order to provide SC push/pull engagement/disengagement with amating optical fiber socket.

In some aspects of the connector, the ferrule is configured to berotationally fixed with respect to the ferrule holder about theconnector axis, the ferrule holder is configured to be rotationallyaligned with respect to the outer housing so that the rotationalorientation of the ferrule with respect to the outer housing can be setduring assembly of the connector at one of one or more predefinedrotational orientations, and a rotational key is provided between theferrule housing and the inner housing.

According to various embodiments of the disclosure, an optical fiberconnector sub-assembly includes a ferrule holder configured to hold aferrule at a front portion of an optical fiber connector, a ferrulehousing configured to slidingly receive the ferrule holder andconfigured to be crimped onto an end of a fiber optic cable thatincludes an optical fiber, and a spring configured to be nonrotatablycoupled with the ferrule holder and the ferrule housing. The spring isconfigured to prevent the ferrule from rotating relative to the end ofthe fiber optic cable while permitting the ferrule holder to slideaxially relative to the ferrule housing, and the spring is configured toreduce a load on the ferrule when a load is applied to the fiber opticcable so as to prevent degradation of a signal being transmitted by thefiber.

In some aspects, the spring is configured to bias the ferrule away fromthe ferrule housing along the connector axis.

In various aspects, the ferrule holder and the ferrule housing areconfigured to move axially relative to one another along the connectoraxis between limits defined by an interaction between the ferrulehousing, the spring, and the ferrule holder.

According to some aspects, the optical fiber connector sub-assembly mayfurther comprise an inner housing configured to be coupled with theferrule housing. According to various aspects, the ferrule holder, theferrule housing, and the inner housing are configured to be rotatablyfixed to one another. In some aspects, the ferrule holder is configuredto slide axially relative to the inner housing.

According to various aspects, a Subscriber Connection (SC) optical fiberconnector may include the aforesaid optical fiber connector with aninner housing and an outer housing. The inner housing is configured todefine a receptacle that is configured to receive a socket that isconfigured to receive a projecting portion of the ferrule. The spring isconfigured such that the projecting portion of the ferrule is springbiased along the connector axis towards the receptacle of the innerhousing. The inner housing is configured to be engaged within the outerhousing, the inner housing and the outer housing being configured tomove relative to each other along the connector axis between limitsdefined by an interaction between the inner housing and the outerhousing in order to provide SC push/pull engagement/disengagement with amating optical fiber socket.

In some aspects of the connector, the ferrule is configured to berotationally fixed with respect to the ferrule holder about theconnector axis, the ferrule holder is configured to be rotationallyaligned with respect to the outer housing so that the rotationalorientation of the ferrule with respect to the outer housing can be setduring assembly of the connector at one of one or more predefinedrotational orientations, and a rotational key is provided between theferrule housing and the inner housing.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be further described, by way ofexample only, and with reference to the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of an exemplary prior art SCconnector;

FIG. 2 is a perspective view of the optical fiber connector sub-assemblyof FIG. 1 when assembled;

FIG. 3 is a perspective view of an exemplary optical fiber connectorsub-assembly in accordance with various aspects of the disclosureterminating an optical fiber cable;

FIG. 4 is a perspective cross-sectional view of the optical fiberconnector sub-assembly of FIG. 3;

FIG. 5 is a perspective view of an exemplary SC connector including theoptical fiber connector sub-assembly of FIG. 3;

FIG. 6 is a top cross-sectional view of the ferrule housing of theoptical fiber connector sub-assembly of FIG. 3;

FIG. 7 is a perspective cross-sectional view of the ferrule housing ofFIG. 6;

FIG. 8 is a perspective view of an exemplary optical fiber connectorsub- assembly in accordance with various aspects of the disclosureterminating an optical fiber cable;

FIG. 9 is a perspective view of the optical fiber connector sub-assemblyof FIG. 8 when assembled;

FIG. 10 is a perspective view of an exemplary SC connector including theoptical fiber connector sub-assembly of FIG. 8;

FIG. 11 is a perspective cross-sectional view of the exemplary SCconnector of FIG. 10;

FIG. 12 is a side cross-sectional view of the exemplary SC connector ofFIG. 10;

FIG. 13 is an exploded perspective view of an exemplary SC connector inaccordance with various aspects of the disclosure;

FIG. 14 is a perspective view of the exemplary SC connector of FIG. 13;

FIG. 15 is an exploded perspective view of the exemplary SC connector ofFIG. 13; and

FIG. 16 is a perspective cross-sectional view of the optical fiberconnector sub-assembly of the connector of FIG. 13.

DETAILED DESCRIPTION OF EMBODIMENTS

FIGS. 1 and 2 show an exemplary prior art SC connector, such as theconnectors disclosed in U.S. patent application Ser. No. 15/887,925, thedisclosure of which is incorporated herein by reference. The exemplarySC connector 100 includes an optical fiber cable 102, a ferrule housingsub-assembly 104, and an outer housing 140 to provide SC push/pullengagement/disengagement with a mating optical fiber socket (not shown).

The cable 102 holds an optical fiber 108, for example, a single strandof 125 μm diameter single mode optical fiber, protected by primary andsecondary buffering layers 110, about 900 μm in diameter, and an outersheath 112, typically 3 mm to 5 mm in diameter. The optical fiber 108 isterminated by a ferrule 114 in a manner well-known to those skilled inthe art and defines a ferrule axis 105 that extends centrally throughthe SC connector 100.

The ferrule housing sub-assembly 104 includes the cylindrical ceramicferrule 114, a ferrule basket 116 in which the ferrule is seated, ahelical spring 117, a ferrule housing 155, and an inner housing 120. Theferrule housing 155 includes a cylindrical sleeve portion 136 and aferrule basket carrier portion 150. The ferrule basket carrier portion150 may include longitudinal slots 180 along the lengths of their outersurfaces that are keyed to projections (not shown) on an inner surfaceof the inner housing 120 to prevent the ferrule housing 155 fromrotating relative to the inner housing 120.

The ferrule basket 116 has a base 115 and a cylindrical stem 122 whichextends from the base 115 in an axial direction away from the ferrule114 towards the cylindrical sleeve portion 136, which is used to make acrimp connection around the optical fiber cable sheathing 112. Thespring 117 is seated around the stem 122 between an annular shoulder 124on the ferrule basket 116 and an annular surface 152 within acylindrical recess 154 of the ferrule basket carrier portion 150. Thestem 122 is slidably seated in a bore of the ferrule housing 155.

During assembly, the ferrule basket 116 and seated ferrule 114 areinserted axially into the recess 154 of the ferrule basket carrierportion 150. The ferrule basket carrier portion 150 has a pair of arms156 that extend axially forwards of the stem 122 on opposite sides ofthe ferrule basket 116. Two pairs of curved fingers 158 are provided,each pair extending in opposite circumferential directions at the end ofeach arm 156. The fingers 158 extend transversely to the length of thearms 156 partially around the circumference of a portion of the ferrule114 nearest a base 115.

The ferrule base 115 has four cycles of crenellations 162 spacedsymmetrically around the circumference of the base and which providefour corresponding channels that extend parallel to the optical fiberaxis 105. These crenellations 162 are in the form of alternatingradially high 165 and low 166 cylindrically shaped regions with thecircumferential and axial extent of each of the high 165 and low 166regions being the same. The high 165 and low 166 regions are separatedby steps 167 that extend in a radial direction. The arms 156 are seatedin opposite radially low regions 166 in a sliding fit with the adjacenthigh regions 165 and reach axially forward of the base 115 andcrenellations 162 so that the fingers 158 engage with the interveningradially high regions 165 on a side 161 of the base 115 opposite theannular surface 124 against which the spring 117 is engaged.

The aforementioned arrangement permits a degree axial movement of theferrule basket carrier portion 150, with movement being thereforelimited in one direction by the compression of the spring 117 betweenthe two annular surfaces 124, 152 and in the other axial direction bythe contact of the fingers 158 with the radially high regions 165 of thecrenellations 162 on the base 115 of the ferrule basket 116. As can beseen from the drawings, the ferrule holder base 115 and ferrule basketcarrier portion 150 also have a common cylindrical outer envelope.

The inner housing 120 has a forward portion 130 that coaxially extendsaround the axially projecting ferrule 114 to define a receptacle 132 fora socket (not shown) to receive a projecting portion of the ferrule 114.

The ferrule basket 116 is free to move backwards inside the ferrulebasket carrier portion 150 and the inner housing 120 when an end face134 of the ferrule 114 comes into contact with a similar end face (notshown) of another optical fiber ferrule when making an opticalconnection.

The ferrule basket carrier portion 150 has a central aperture (notshown) through which the optical fiber 108 and buffering 110 pass andhas in a rear-most portion the sleeve 136 configured to receive and becrimped to the cable sheathing 112. In some aspects, a strain-reliefsleeve (not shown), for example, a boot, may be provided around thejunction of the optical fiber cable 102 and the ferrule housingsub-assembly 104.

An outer housing 140 is press-fitted axially over the assembled ferrulehousing sub-assembly 104. Once the inner housing 120 and outer housing140 are engaged together, the inner and outer housings are relativelymoveable with respect to each other along the ferrule axis 105 betweenlimits defined by an interaction between the inner housing 120 and theouter housing 140 provided by projections 142 on a pair of oppositesides of the inner housing 120 and a pair of apertures 144 in the outerhousing. The projections 142 and apertures 144 interact with sprungfeatures inside a matching socket (not shown) to provide SC push/pullengagement/disengagement configured to mate with an optical fibersocket.

The rotational orientation of the ferrule basket carrier portion 150 maybe set at one of four orientations relative to the ferrule 114 in theferrule basket 116 owing to the seating of the arms 156 in thecrenellations. In this way, a first rotational key is provided betweenthe ferrule basket 116 and the ferrule basket carrier portion 150 suchthat the ferrule basket 116 and the ferrule basket carrier portion 150are rotatably fixed to one another (i.e., are not rotatable relative toone another).

The optical fiber 108 is therefore terminated in a sub-assembly referredto herein as an optical fiber connector sub-assembly 160, as illustratedin FIG. 2. During assembly of the optical fiber connector sub-assembly160, the arms 156 and the fingers 158, which each have a chamfered taper164 on an inner forward surface, flex outwardly over the base 115 of theferrule holder 114 until the fingers 158 snap radially inwards intoengagement with the forwards surface 161 of the ferrule basket base 115.

In both cases, the resulting optical fiber connector sub-assembly 160 istherefore mechanically whole or integral, both as regards the componentsforming the sub-assembly and as regards the mechanical connection of thesub-assembly to the optical fiber cable 102. The sub-assembly cannotcome apart without first prizing the fingers 158 back over the ferulebasket base 115. The ferrule basket carrier portion 150 has an outerdiameter which is preferably no more than that of the widest portion ofthe ferrule basket 116, i.e., the ferrule basket base 115.

After the insertion has been performed, the assembly of the SC opticalfiber connector 100 is completed as follows. The inner housing 120 isinserted in an axial direction over the projecting ferrule 114 andsurrounding ferrule basket carrier portion 150. The external shape ofthe inner housing 120 where this interacts with the outer housing 140 isthe same as with conventional connectors. The outer housing 140therefore is snap-fitted over the inner housing 120, after which the SCconnector 100 is fully compatible with conventional connectors andconventional optical fiber sockets.

Referring now to FIGS. 3-7, an exemplary optical fiber connector 200,for example, an SC connector, in accordance with various aspects of thedisclosure is illustrated and described. The connector 200 includes anoptical fiber cable 102, a ferrule housing sub-assembly 204, and anouter housing (not shown) to provide SC push/pullengagement/disengagement with a mating optical fiber socket (not shown).

The ferrule housing sub-assembly 204 includes a cylindrical ceramicferrule 214, a ferrule basket 216 in which the ferrule 214 is seated, ahelical spring 217, a ferrule housing 255, and an inner housing 220. Theferrule housing 255 includes a front tube portion 250, a rear tubeportion 236, and a connecting tube portion 237 between the front andrear tube portions 250, 236. The connecting tube portion 237 has asmaller outside diameter than the adjacent front tube portion 250 andrear tube portion 236.

The ferrule basket 216 has a base 215 and a cylindrical stem 222 whichextends from the base 215 in an axial direction away from the ferrule214 towards the rear tube portion 236, which is used to make a crimpconnection around the optical fiber cable sheathing 212. The spring 217is seated around the stem 222 between an annular shoulder 224 on theferrule basket 216 and an annular surface 252 within a cylindricalrecess 254 at a rearward end of the front tube portion 250. The stem 222slidably extends through an opening 239 at the rearward end of the fronttube portion 250 and into the connecting tube portion 237. A rearwardend of the stem 222 includes a flared end portion 223. The flared endportion 223 has a diameter greater than a diameter of the opening 239such that forward axial movement of the stem 222 relative to the ferrulehousing 255 is limited by interaction of the flared end portion 223 witha rearward-facing shoulder 241 in the connecting tube portion 237 at theopening 239.

The ferrule basket 216 is configured to be inserted axially into therecess 254 of the front tube portion 250. The front tube portion 250 hasa pair of diametrically opposed arms 256 that extend axially forward ofthe stem 222 on opposite sides of the ferrule basket 216. The ferrulebase 215 has four cycles of crenellations 262 spaced symmetricallyaround the circumference of the base and which provide fourcorresponding channels that extend parallel to the optical fiber axis205. These crenellations 262 are in the form of alternating radiallyhigh 265 and low 266 cylindrically shaped regions with thecircumferential and axial extent of each of the high 265 and low 266regions being the same. The high 265 and low 266 regions are separatedby steps 267 that extend in a radial direction. The arms 256 are seatedin two opposite radially low regions 266 in a sliding fit with theadjacent high regions 265.

The aforementioned arrangement permits a degree of axial movement of theferrule basket 216 and ferrule 214 relative to the ferrule housing 255,with movement being therefore limited in one direction by thecompression of the spring 217 between the two annular surfaces 224, 252and in the other axial direction by the contact of the flared endportion 223 of the stem 222 with the rearward-facing shoulder 241 in theconnecting tube portion 237. As can be seen from the drawings, theferrule holder base 215 and front tube portion 250 also have a commoncylindrical outer envelope.

The inner housing 220 has a forward portion 230 that coaxially extendsaround the axially projecting ferrule 214 to define a receptacle 232 fora socket (not shown) configured to receive a projecting portion of theferrule 214. The ferrule basket 216 is free to move backwards inside thefront tube portion 250 and the inner housing 220 when an end face 234 ofthe ferrule 214 comes into contact with a similar end face (not shown)of another optical fiber ferrule when making an optical connection.

The front tube portion 250 of the ferrule housing 255 may includelongitudinal notches 270 in its top and bottom outer surfaces that arekeyed to axially extending projections 272 (FIGS. 6 and 7) on top andbottom inner surfaces of the inner housing 220 to prevent the ferrulehousing 255 from rotating relative to the inner housing 220. As shown inFIG. 4, the notches 270 are axially aligned with two of the low regions266 of the crenellations 262 that are not occupied by the arms 256. Thedepth of the notches 270 is less than a depth of the low regions 266relative to outer profiles of the front tube portion 250 and the highregions 265 of the ferrule base 215, which are substantially the same asone another.

Referring to FIG. 5, the inner housing 220 may include a rear portion226 including one or more barbs 228 configured to receive a strainrelief boot (not shown) thereon such that the barb(s) 228 prevents thestrain relief boot from being removed when a force less than apredetermined pulling force is applied to the cable or the boot. Whenthe boot is coupled with the rear portion 226 of the inner housing 220,a forward end of the boot is rearward of a rear end of the inner housing220. A flange portion 231 at the rear end of the inner housing 220limits rearward movement of the outer housing 240 relative to the innerhousing 220 during assembly such that when inner housing 220 and theouter housing are assembled together, the boot is spaced rearwardly fromthe outer housing 240.

Referring now to FIGS. 6 and 7 (illustrating only the bottom projection272), a rearward end of the receptacle 232 is bounded by a wall portion233 having an opening 235 with a dimension that is smaller than across-sectional dimension of the receptacle. The projections 272 extendrearward from the wall portion 233 and radially inward from the wallportion 233 of the inner housing 220. The projections 272 include afirst portion 276 having a width in a direction transverse to the axialdirection that tapers from an inner wall 229 to a second portion 278.The second portion 278 of the projection 272 has a substantiallyconstant width dimension. The first portion 276 and the second portion278 have a substantially contact radial thickness. The projections 272include a third portion 280 extending from the second portion 278. Thethird portion 280 includes a substantially same width dimension as thesecond portion 278, but the third portion 280 includes a radiallythickness that tapers from the second portion 278 to a smallersubstantially constant thickness along a majority of a length of thethird portion 280. At a rearward end of the third portion 280, thethickness tapers to the inner wall 229 of the inner housing 220.Although only the bottom projection 272 is illustrated, it should beunderstood that the top wall of the inner housing 220 includes anidentical projection.

As a result of the aforementioned structures of the projections 272, thenotches 270, and the low regions 266, the inner housing 220 and theferrule housing 255 are rotatably coupled to one another. As the innerhousing 220 is slipped over the ferrule housing 255, the low regions 266and notches 270 are aligned with the projections 272. A width dimensionof the low regions 266 and notches 270 is greater than the width of thesecond and third portions 278, 280 of the projections 272 to facilitateinsertion of the ferrule housing 255 into the inner housing 220. The lowregions 266 have a width dimension sized to engage the first taperedportion 276 of the projections 272 so as to be spaced from a rearsurface of the wall portion 233 of the receptacle 232. A total length ofthe first and second portions 276, 278 of the projections 272 is sizedto extend through the low regions 266 in the axial direction withoutentering the notches 270, thus allowing the ferrule basket 216 to slidealong the second portion 278 when the ferrule basket 216 slides axiallyrelative to the ferrule housing 255. The third portion 280 has a lengththat extends into the notches 270, while allowing the inner housing 220and the ferrule basket 216 to slide axially relative to the ferrulehousing 255 without such axial sliding movement being limited by thethicker second portion 278.

The front tube portion 250 has a central aperture (not shown) throughwhich the optical fiber 108 and buffering 110 pass and has in arear-most portion the sleeve 236 configured to receive and be crimped tothe cable sheathing 112. In some aspects, a strain-relief sleeve (notshown), for example, a boot, may be provided around the junction of theoptical fiber cable 102 and the ferrule housing sub-assembly 204.

An outer housing is press-fitted axially over the assembled ferrulehousing sub-assembly 204. Once the inner housing 220 and outer housingare engaged together, the inner and outer housings are relativelymoveable with respect to each other along the ferrule axis 205 betweenlimits defined by an interaction between the inner housing 220 and theouter housing provided by projections 242 on a pair of opposite sides ofthe inner housing 220 and a pair of apertures (not shown) in the outerhousing. The projections 242 and apertures interact with spring featuresinside a matching socket (not shown) to provide SC push/pullengagement/disengagement configured to mate with an optical fibersocket.

The rotational orientation of the front tube portion 250 may be set atone of four orientations relative to the ferrule 214 in the ferrulebasket 214 owing to the seating of the arms 256 in the crenellations262. In this way, a first rotational key is provided between the ferrulebasket 216 and the front tube portion 250 such that the ferrule basket216 and the front tube portion 250 are rotatably fixed to one another(i.e., are not rotatable relative to one another).

The optical fiber 108 is therefore terminated in a sub-assembly referredto herein as an optical fiber connector sub-assembly 260. The resultingoptical fiber connector sub-assembly 260 is therefore mechanically wholeor integral, both as regards the components forming the sub-assembly andas regards the mechanical connection of the sub-assembly to the opticalfiber cable 102. The front tube portion 250 has an outer diameter whichis preferably no more than that of the widest portion of the ferrulebasket 216, i.e., the crenellations 262 of the ferrule basket base 215.

After the insertion has been performed, the assembly of the SC opticalfiber connector 200 is completed as follows. The inner housing 220 isslid in an axial direction over the projecting ferrule 214 andsurrounding front tube portion 250. The inner housing 220 includeslatches 221 on opposite side walls 223. For example, the latches 221 maybe disposed in cutouts 225 in the side walls 223 of the inner housing.The latches 221 may extend forwardly from a rearward wall 227 of thecutouts 225. When the inner housing 220 is slid over the front tubeportion 250, the latches 221 are configured to deflect outwardly andwhen the connecting tube portion 237 of the ferrule housing 255 reachesthe latches 221, the latches 221 move inwardly toward the connectingtube portion 237 to a position in the annular groove 238 between thefront tube portion 250 and the rear tube portion 236, thereby fixing theposition of the ferrule housing 255 relative to the inner housing 220.The external shape of the inner housing 220 where this interacts withthe outer housing 240 is the same as or similar to conventionalconnectors. The outer housing therefore is snap-fitted over the innerhousing 220, after which the SC connector 200 is fully compatible withconventional connectors and conventional optical fiber sockets.

Referring now to FIGS. 8-12, an exemplary optical fiber connector 300,for example, an SC connector, in accordance with various aspects of thedisclosure is illustrated and described. The connector 300 includes anoptical fiber cable 102, a ferrule housing sub-assembly 304, and anouter housing 340 to provide SC push/pull engagement/disengagement witha mating optical fiber socket (not shown).

The ferrule housing sub-assembly 304 includes a cylindrical ceramicferrule 314, a ferrule basket 316 in which the ferrule 314 is seated, ahelical spring 317, a ferrule housing 355, and an inner housing 320. Theferrule housing 355 includes a front tube portion 350 connected with arear tube portion 336 via a press-fit connection 337. At the press-fitconnection 337, the rear tube portion 336 has a smaller outside diameterthan the front tube portion 350 such that the rear tube portion 336 isreceived in the front tube portion 350. The overlap of the front tubeportion 350 relative to the rear tube portion 350 is limited by a flange351 extending radially outward from an outer surface of the rear tubeportion 350. At a rearward side of the flange 351 (i.e., on an oppositeside of flange 351 relative to the front tube portion 350), the outersurface of the rear tube portion 350 may include an annular groove 353.

The ferrule basket 316 has a base 315 and a cylindrical stem 322 thatextends from the base 315 in an axial direction away from the ferrule314 towards the rear tube portion 336, which is used to make a crimpconnection around the optical fiber cable sheathing 112. The spring 317is seated around a portion of the stem 322 between an annular shoulder324 on the stem 322 and an annular surface 352 within a cylindricalrecess 354 defined by an inwardly extending wall 359 of the flange 351at a rearward end of the front tube portion 350. The stem 322 slidablyextends through an opening 339 at a forward end of the front tubeportion 350. A rearward end of the stem 222 is spaced from the inwardlyextending wall 359, thereby permitting a degree of pivoting movementbetween the ferrule basket 316 and the ferrule housing 355.

The ferrule basket 316 is configured to be inserted axially into therecess 354 of the front tube portion 350. A top surface of the base 315has a radially extending protrusion 362 near a forward end of theferrule basket. A top surface of the front tube portion 350 has anaxially extending longitudinal slot 356 configured to slidingly receivethe protrusion. The aforementioned arrangement permits a degree of axialmovement of the ferrule basket 316 and ferrule 314 relative to the fronttube portion 350 of the ferrule housing 355, with movement beingtherefore limited in one direction by the compression of the spring 317between the two annular surfaces 324, 352 and in the other axialdirection by the contact of the protrusion 362 with a forward end wall357 of the slot 356.

As shown in FIGS. 10-12, the inner housing 320 has a forward portion 330that coaxially extends around the axially projecting ferrule 314 todefine a receptacle 332 for a socket (not shown) configured to receive aprojecting portion of the ferrule 314. The ferrule basket 316 is free tomove backwards inside the front tube portion 350 and the inner housing320 when an end face 334 of the ferrule 314 comes into contact with asimilar end face (not shown) of another optical fiber ferrule whenmaking an optical connection.

The front tube portion 350 of the ferrule housing 355 may include alongitudinal notch 370 in its bottom outer surface that is keyed to anaxially extending projection 374 on the bottom inner surface of theinner housing 320 to prevent the ferrule housing 355 from rotatingrelative to the inner housing 320. A rearward end of the receptacle 332is bounded by a wall portion 333 having an opening 335 with a dimensionthat is smaller than a cross-sectional dimension of the receptacle 332.The projection 372 extends rearward from the wall portion 333 andradially inward from an inner wall 329 of the inner housing 320. As aresult of the aforementioned structures of the projection 372 and thenotch 370, the inner housing 320 and the ferrule housing 355 arerotatably coupled to one another. As the inner housing 320 is slippedover the ferrule housing 355, the notch 370 is aligned with theprojection 372. The ferrule housing 355 has a central aperture 357through which the optical fiber 108 and buffering 110 pass and has in arear-most portion the rear tube portion 336 configured to receive and becrimped to the cable sheathing 112.

In some aspects, as shown in FIG. 11, a boot 390 is provided around thejunction of the optical fiber cable 102 and the ferrule housingsub-assembly 304 and includes at least one projection 392 extendingradially outward and configured to be receiving in an opening 341 in anouter housing 340 to interlock the boot 390 with the outer housing 340.Compared with the embodiment of FIG. 5, where a strain relief boot (notshown) is configured to be coupled with barbs 228 that are spacedrearward from the rear end of the outer housing 240, in the presentembodiment, a forward portion of the boot 390 is configured to bereceived by a rear end of the outer housing 340 such that the outerhousing 340 overlaps the forward portion of the boot 390, which includesthe at least one projection. As a result, the outer housing 340 and theboot 390 are configured to shorten an overall length of the connector300, thereby reducing a load transferred to the ferrule 316 when a loadis applied to the cable 102 and/or the boot 390 and/or a rear end of theconnector 300, for example, in a direction transverse to the connectoraxis, as would be understood by persons of ordinary skill in the art.

The outer housing 340 may be press-fitted axially over the assembledferrule housing sub-assembly 304. Once the inner housing 320 and outerhousing 340 are engaged together, the inner and outer housings arerelatively moveable with respect to each other along the ferrule axis305 between limits defined by an interaction between the inner housing320 and the outer housing 340 provided by projections 342 on a pair ofopposite sides of the inner housing 320 and a pair of apertures 344 inthe outer housing. The projections 342 and apertures 344 interact withspring features inside a matching socket (not shown) to provide SCpush/pull engagement/disengagement configured to mate with an opticalfiber socket.

The rotational orientation of the front tube portion 350 is set to oneorientation relative to the ferrule 314 in the ferrule basket 316 owingto the cooperation between the protrusion 362 and the slot 356. In thisway, a first rotational key is provided between the ferrule basket 316and the front tube portion 350 such that the ferrule basket 316 and thefront tube portion 350 are rotatably fixed to one another (i.e., are notrotatable relative to one another). The optical fiber 108 is thereforeterminated in a sub-assembly referred to herein as an optical fiberconnector sub-assembly 360. The resulting optical fiber connectorsub-assembly 360 is therefore mechanically whole or integral, both asregards the components forming the sub-assembly and as regards themechanical connection of the sub-assembly to the optical fiber cable102.

After the insertion has been performed, the assembly of the SC opticalfiber connector 300 is completed as follows. The inner housing 320 isslid in an axial direction over the projecting ferrule 314 andsurrounding front tube portion 350. The inner housing 320 includeslatches 321 on opposite side walls 323. For example, the latches 321 maybe disposed in cutouts 325 in the side walls 323 of the inner housing.The latches 321 may extend rearward from a forward wall 329 of thecutouts 325. When the inner housing 320 is slid over the front tubeportion 350, the latches 321 are configured to deflect outwardly andwhen the annular groove 353 of the ferrule housing 355 reaches thelatches 321, the latches 321 move inwardly toward the annular groove 353to a position in the annular groove 353, thereby fixing the position ofthe ferrule housing 355 relative to the inner housing 320. The externalshape of the inner housing 320 where this interacts with the outerhousing 340 is the same as or similar to conventional connectors. Theouter housing 340 therefore is snap-fitted over the inner housing 320,after which the SC connector 300 is fully compatible with conventionalconnectors and conventional optical fiber sockets.

Referring now to FIGS. 13-16, an exemplary optical fiber connector 400,for example, an SC connector, in accordance with various aspects of thedisclosure is illustrated and described. The connector 400 includes anoptical fiber cable 102, a ferrule housing sub-assembly 404, and anouter housing 440 to provide SC push/pull engagement/disengagement witha mating optical fiber socket (not shown).

The ferrule housing sub-assembly 404 includes a cylindrical ceramicferrule 414, a ferrule basket 416 in which the ferrule 414 is seated, ahelical spring 417, a ferrule housing 455, and an inner housing 420. Theferrule housing 455 includes a front tube portion 450 connected with arear tube portion 436 via a press-fit connection 437. At the press-fitconnection 437, the rear tube portion 436 has a smaller outside diameterthan the front tube portion 450 such that the rear tube portion 436 isreceived in the front tube portion 450. The overlap of the front tubeportion 450 relative to the rear tube portion 450 is limited by a flange451 extending radially outward from an outer surface of the rear tubeportion 450. At a rearward side of the flange 451 (i.e., on an oppositeside of flange 451 relative to the front tube portion 450), the outersurface of the rear tube portion 450 may include an annular groove 453.

The ferrule basket 416 has a base 415 and a cylindrical stem 422 thatextends from the base 415 in an axial direction away from the ferrule414 towards the rear tube portion 436, which is used to make a crimpconnection around the optical fiber cable sheathing 112. As shown inFIG. 16, crimping of the rear tube portion 436 creates a mushroomportion 113 at the front of the cable sheathing 112 to aid with cableretention. The spring 417 is pressed onto an outer surface of a portionof the stem 422 and into an inner surface of a forward portion of therear tube portion 436. The spring is held between an annular shoulder424 on the stem 422 and an annular surface 452 within a cylindricalrecess 454 defined by an inwardly extending wall 459 of the flange 451at a rearward end of the front tube portion 450. The stem 422 slidablyextends through an opening 439 at a forward end of the rear tube portion436. A rearward end of the stem 422 is spaced radially inward from theinwardly extending wall 459, thereby permitting a degree of pivotingmovement between the ferrule basket 416 and the ferrule housing 455.

The ferrule basket 416 is configured to be axially slidable in a recess454 of the front tube portion 450. A forward end of the ferrule basket416 includes a sloped surface 426, and a rearward directed wall at aforward end of the front tube portion 450 includes a similar sloped wall456. The sloped wall 456 of the front tube portion 450 is sized andconfigured to relative to the sloped surface 426 of the ferrule basket416 to prevent the ferrule basket 416 from exiting through the forwardend of the front tube portion. The aforementioned arrangement providesthe ferrule 414 and ferrule basket 416 with freedom to pivot and floatrelative to the ferrule housing 455 and permits a degree of axialmovement of the ferrule basket 416 and ferrule 414 relative to the fronttube portion 450 of the ferrule housing 455. Such axial movement islimited in one direction by the compression of the spring 417 betweenthe two annular surfaces 424, 452 and in the other axial direction bythe contact of the sloped surface 426 and the sloped wall 456.

As shown in FIGS. 14 and 15, the inner housing 420 has a forward portion430 that coaxially extends around the axially projecting ferrule 414 todefine a receptacle 432 for a socket (not shown) configured to receive aprojecting portion of the ferrule 414. The ferrule basket 416 is free tomove backwards inside the front tube portion 450 and the inner housing420 when an end face 434 of the ferrule 414 comes into contact with asimilar end face (not shown) of another optical fiber ferrule whenmaking an optical connection.

The front tube portion 450 of the ferrule housing 455 may include akeyed outer surface 470 at its front end. The keyed outer surface 470 isconfigured to match a keyed inner surface of the inner housing 420 toprevent the ferrule housing 455 from rotating relative to the innerhousing 420. For example, the keyed outer surface 470 may include fourflattened region spaced equidistantly about an outer periphery at thefront end of the front tube portion 450, and the inner housing 420 mayinclude a square receptacle configured to receive the keyed outersurface 470. As a result of the aforementioned structures of the keyedouter surface 470 and inner housing 420, the inner housing 420 and theferrule housing 455 are rotatably coupled to one another.

The inner housing 420 may also include at least projection 428projecting inwardly toward the ferrule axis 405. The at least oneprojection 428 is configured such that, as the inner housing 420 isslipped over the ferrule housing 455, the at least one projection 428 isaligned with the and received by the annular groove 453 to secure theinner housing 420 with the ferrule housing 455 to prevent relative axialmovement. As shown in FIG. 15, in some embodiments, the inner housingmay include two projections 428.

The ferrule housing 455 has a central aperture 457 through which theoptical fiber 108 and buffering 110 pass and has in a rear-most portionthe rear tube portion 436 configured to receive and be crimped to thecable sheathing 112. A boot 490 is provided around the junction of theoptical fiber cable 102 and the ferrule housing sub-assembly 404 andincludes at least one projection 492 extending radially outward andconfigured to be receiving in an opening 441 in an outer housing 440 tointerlock the boot 490 with the outer housing 440. Compared with theembodiment of FIG. 5, where a strain relief boot (not shown) isconfigured to be coupled with barbs 228 that are spaced rearward fromthe rear end of the outer housing 240, in the present embodiment, aforward portion of the boot 490 is configured to be received by a rearend of the outer housing 440 such that the outer housing 440 overlapsthe forward portion of the boot 490, which includes the at least oneprojection. As a result, the outer housing 440 and the boot 490 areconfigured to shorten an overall length of the connector 400, therebyreducing a load transferred to the ferrule 416 when a load is applied tothe cable 102 and/or the boot 490 and/or a rear end of the connector400, for example, in a direction transverse to the connector axis, aswould be understood by persons of ordinary skill in the art.

Once the inner housing 420 and outer housing 440 are engaged together,the inner and outer housings are relatively moveable with respect toeach other along the ferrule axis 405 between limits defined by aninteraction between the inner housing 420 and the outer housing 440provided by projections 442 on a pair of opposite sides of the innerhousing 420 and a pair of apertures 444 in the outer housing. Theprojections 442 and apertures 444 interact with spring features inside amatching socket (not shown) to provide SC push/pullengagement/disengagement configured to mate with an optical fibersocket.

The ferrule housing 455 and the ferrule basket 416 are rotatably fixedto one another (i.e., are not rotatable relative to one another) by thespring 417 being press fitted onto the ferrule basket 416 and into therear tube portion 436 of the ferrule housing 455. The optical fiber 108is therefore terminated in a sub-assembly referred to herein as anoptical fiber connector sub-assembly 460. The resulting optical fiberconnector sub-assembly 460 is therefore mechanically whole or integral,both as regards the components forming the sub-assembly and as regardsthe mechanical connection of the sub-assembly to the optical fiber cable102.

After the insertion has been performed, the assembly of the SC opticalfiber connector 400 is completed as follows. The inner housing 420 isslid in an axial direction over the projecting ferrule 414 andsurrounding front tube portion 450. The inner housing 420 includes oneor more projections 428 configured to deflect outwardly and when theannular groove 453 of the ferrule housing 455 reaches the projections428, the projections 428 move inwardly toward the annular groove 453 toa position in the annular groove 453, thereby fixing the position of theferrule housing 455 relative to the inner housing 420. The externalshape of the inner housing 420 where this interacts with the outerhousing 440 is the same as or similar to conventional connectors. Theouter housing 440 is then slid over the inner housing 420 and until theprojection 492 of the boot 490 is snap-fitted into the opening 441 inthe outer housing 440, after which the SC connector 400 is fullycompatible with conventional connectors and conventional optical fibersockets.

Additional embodiments include any one of the embodiments describedabove, where one or more of its components, functionalities orstructures is interchanged with, replaced by or augmented by one or moreof the components, functionalities, or structures of a differentembodiment described above.

It should be understood that various changes and modifications to theembodiments described herein will be apparent to those skilled in theart. Such changes and modifications can be made without departing fromthe spirit and scope of the present disclosure and without diminishingits intended advantages. It is therefore intended that such changes andmodifications be covered by the appended claims.

Although several embodiments of the disclosure have been disclosed inthe foregoing specification, it is understood by those skilled in theart that many modifications and other embodiments of the disclosure willcome to mind to which the disclosure pertains, having the benefit of theteaching presented in the foregoing description and associated drawings.It is thus understood that the disclosure is not limited to the specificembodiments disclosed herein above, and that many modifications andother embodiments are intended to be included within the scope of theappended claims. Moreover, although specific terms are employed herein,as well as in the claims which follow, they are used only in a genericand descriptive sense, and not for the purposes of limiting the presentdisclosure, nor the claims which follow.

What is claimed is:
 1. An optical fiber connector sub-assembly,comprising: a ferrule configured to hold an optical fiber therein alongan axis of an optical fiber connector; a ferrule holder configured tohold the ferrule at a front portion of the connector; a ferrule housingincluding a front portion configured to slidingly receive the ferruleholder and a rear portion configured to be crimped onto an end of afiber optic cable that includes the optical fiber; an inner housingconfigured to be coupled with the ferrule housing; a spring having afirst end configured to be press fit onto a radially outer surface ofthe ferrule holder and a second end configured to be press fit into aradially inner surface of the ferrule housing; wherein the ferruleholder, the ferrule housing, and the inner housing are configured to berotatably fixed to one another; wherein the ferrule holder is configuredto slide axially relative to the inner housing; wherein the ferruleholder and the ferrule housing are configured to move axially relativeto one another along the connector axis between limits defined by aninteraction between the ferrule housing, the spring, and the ferruleholder; wherein the spring is configured to prevent the ferrule fromrotating relative to the end of the fiber optic cable while permittingthe ferrule holder to slide axially relative to the ferrule housing;wherein the spring is configured to reduce a load on the ferrule when aload is applied to the fiber optic cable so as to prevent degradation ofa signal being transmitted by the fiber.
 2. The optical fiber connectorsub-assembly of claim 1, wherein the spring is configured to bias theferrule away from the ferrule housing along the connector axis.
 3. ASubscriber Connection (SC) optical fiber connector comprising: theoptical fiber connector sub-assembly as claimed in claim 1; an outerhousing; wherein the inner housing is configured to define a receptaclethat is configured to receive a socket that is configured to receive aprojecting portion of the ferrule; wherein the spring is configured suchthat the projecting portion of the ferrule is spring biased along theconnector axis towards the receptacle of the inner housing; wherein theinner housing is configured to be engaged within the outer housing; andwherein the inner housing and the outer housing are configured to moverelative to each other along the connector axis between limits definedby an interaction between the inner housing and the outer housing inorder to provide SC push/pull engagement/disengagement with a matingoptical fiber socket.
 4. The SC optical fiber connector of claim 3,wherein the ferrule is configured to be rotationally fixed with respectto the ferrule holder about the connector axis; wherein the ferruleholder is configured to be rotationally aligned with respect to theouter housing so that the rotational orientation of the ferrule withrespect to the outer housing can be set during assembly of the connectorat one of one or more predefined rotational orientations; and wherein arotational key is provided between the ferrule housing and the innerhousing.
 5. An optical fiber connector sub-assembly, comprising: aferrule configured to hold an optical fiber therein along an axis of anoptical fiber connector; a ferrule holder configured to hold the ferruleat a front portion of the connector; a ferrule housing including a frontportion configured to slidingly receive the ferrule holder and a rearportion configured to terminate an end of a fiber optic cable thatincludes the optical fiber; a spring having a first end configured to benonrotatably coupled with the ferrule holder and a second end configuredto be nonrotatably coupled with the ferrule housing; wherein the springis configured to prevent the ferrule from rotating relative to the endof the fiber optic cable while permitting the ferrule holder to slideaxially relative to the ferrule housing; and wherein the spring isconfigured to reduce a load on the ferrule when a load is applied to thefiber optic cable so as to prevent degradation of a signal beingtransmitted by the fiber.
 6. The optical fiber connector sub-assembly ofclaim 5, wherein the spring is configured to bias the ferrule away fromthe ferrule housing along the connector axis.
 7. The optical fiberconnector sub-assembly of claim 5, wherein the ferrule holder and theferrule housing are configured to move axially relative to one anotheralong the connector axis between limits defined by an interactionbetween the ferrule housing, the spring, and the ferrule holder.
 8. Theoptical fiber connector sub-assembly of claim 5, further comprising aninner housing configured to be coupled with the ferrule housing.
 9. Theoptical fiber connector sub-assembly of claim 8, wherein the ferruleholder, the ferrule housing, and the inner housing are configured to berotatably fixed to one another.
 10. The optical fiber connectorsub-assembly of claim 8, wherein the ferrule holder is configured toslide axially relative to the inner housing.
 11. A Subscriber Connection(SC) optical fiber connector comprising: the optical fiber connectorsub-assembly as claimed in claim 8; an outer housing; wherein the innerhousing is configured to define a receptacle that is configured toreceive a socket that is configured to receive a projecting portion ofthe ferrule; wherein the spring is configured such that the projectingportion of the ferrule is spring biased along the connector axis towardsthe receptacle of the inner housing; and wherein the inner housing isconfigured to be engaged within the outer housing, the inner housing andthe outer housing being configured to move relative to each other alongthe connector axis between limits defined by an interaction between theinner housing and the outer housing in order to provide SC push/pullengagement/disengagement with a mating optical fiber socket.
 12. The SCoptical fiber connector of claim 11, wherein the ferrule is configuredto be rotationally fixed with respect to the ferrule holder about theconnector axis; wherein the ferrule holder is configured to berotationally aligned with respect to the outer housing so that therotational orientation of the ferrule with respect to the outer housingcan be set during assembly of the connector at one of one or morepredefined rotational orientations; and wherein a rotational key isprovided between the ferrule housing and the inner housing.
 13. Anoptical fiber connector sub-assembly, comprising: a ferrule holderconfigured to hold a ferrule at a front portion of an optical fiberconnector; a ferrule housing configured to slidingly receive the ferruleholder and configured to be coupled with an end of a fiber optic cablethat includes an optical fiber; a spring configured to be nonrotatablycoupled with the ferrule holder and the ferrule housing; wherein thespring is configured to prevent the ferrule from rotating relative tothe end of the fiber optic cable while permitting the ferrule holder toslide axially relative to the ferrule housing; and wherein the spring isconfigured to reduce a load on the ferrule when a load is applied to thefiber optic cable so as to prevent degradation of a signal beingtransmitted by the fiber.
 14. The optical fiber connector sub-assemblyof claim 13, wherein the spring is configured to bias the ferrule awayfrom the ferrule housing along the connector axis.
 15. The optical fiberconnector sub-assembly of claim 13, wherein the ferrule holder and theferrule housing are configured to move axially relative to one anotheralong the connector axis between limits defined by an interactionbetween the ferrule housing, the spring, and the ferrule holder.
 16. Theoptical fiber connector sub-assembly of claim 13, further comprising aninner housing configured to be coupled with the ferrule housing.
 17. Theoptical fiber connector sub-assembly of claim 16, wherein the ferruleholder, the ferrule housing, and the inner housing are configured to berotatably fixed to one another.
 18. The optical fiber connectorsub-assembly of claim 16, wherein the ferrule holder is configured toslide axially relative to the inner housing.
 19. A Subscriber Connection(SC) optical fiber connector comprising: the optical fiber connectorsub-assembly as claimed in claim 16; an outer housing; wherein the innerhousing is configured to define a receptacle that is configured toreceive a socket that is configured to receive a projecting portion ofthe ferrule; wherein the spring is configured such that the projectingportion of the ferrule is spring biased along the connector axis towardsthe receptacle of the inner housing; and wherein the inner housing isconfigured to be engaged within the outer housing, the inner housing andthe outer housing being configured to move relative to each other alongthe connector axis between limits defined by an interaction between theinner housing and the outer housing in order to provide SC push/pullengagement/disengagement with a mating optical fiber socket.
 20. The SCoptical fiber connector of claim 19, wherein the ferrule is configuredto be rotationally fixed with respect to the ferrule holder about theconnector axis; wherein the ferrule holder is configured to berotationally aligned with respect to the outer housing so that therotational orientation of the ferrule with respect to the outer housingcan be set during assembly of the connector at one of one or morepredefined rotational orientations; and wherein a rotational key isprovided between the ferrule housing and the inner housing.